110k Miles only getting 29MPG

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Frank Gomez, Jun 17, 2019.

  1. Frank Gomez

    Frank Gomez New Member

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    Location:
    Sarasota, FL
    Vehicle:
    2010 Prius
    Model:
    V
    We have a 2010 Prius V with 110k miles on it. We've taken very good are of it.

    Over the past few years the gas mileage was in the high 30s / low 40s but since the last few recalls it has plummeted. We've taken it to our normal mechanic who said nothing is wrong w/ the car and perhaps the Toyota Dealer would be able to help. The Toyota dealer "reset" the car (which from my understanding from a 3rd party means disconnecting the cable from the negative terminal of the 12V battery for a minute or two.) Anyway. I'm very frustrated b/c without any error codes I know nothing. Why would I replace the battery without knowing FOR SURE what is wrong w/ the car. How do I find someone to TRULY diagnose the car vs. waiting for a failure.
     
  2. bisco

    bisco cookie crumbler

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    welcome!

    who told you to replace the battery?

    test the 12v

    clean the egr circuit

    clean the throttle body

    check the spark plugs

    what tires and pressures are you running?

    check the air and cabin filters

    check the oil level

    without codes, it's a guessing game

    all the best!(y)
     
  3. Frank Gomez

    Frank Gomez New Member

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    2010 Prius
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    V
    Thanks, No one said to, I just know when my sister's battery died (2 mos ago on 2007 Prius) she said mileage started lagging bad.
    12V - tested, Tires are Continental True Contact (sticky in the rain more important than mileage), normal pressures., Filters changed regularly / inspected. Oil is fine. That leaves EGR circuit, Spark Plugs, Bus Bars.. Thanks for suggestions!
     
    Raytheeagle likes this.
  4. cnc97

    cnc97 Senior Member

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    Three
    If you are not seeing any check engine light or the “Check Hybrid System” message, it is very likely that you have a brake dragging. Any type of hybrid system malfunction will give one or the other. The brakes won’t. Drive it a few miles, then get out and put your hand close to the wheels, one at a time. They should feel about the same temperature at all four wheels. The hottest one is the one dragging. If one is dragging, the hardware, brake hose, or calipers are suspect.
     
  5. Frank Gomez

    Frank Gomez New Member

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    2010 Prius
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    V
    Wow! Never imagined that. I'll check!
     
  6. cnc97

    cnc97 Senior Member

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    Vehicle:
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    Model:
    Three
    After a drive, if you jack up the wheels one at a time (set the parking brake when you lift the front end so you can put the car in neutral), or have the thing put on a lift in neutral, the wheels should spin a couple of rotations by themselves if given a spin by hand. Think of the big wheel on “The Price Is Right”. They shouldn’t stop right away.
     
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